1. Field of the Invention
The present invention is relating to an electronic component module attached to a circuit substrate, for covering an electronic component with a shield component, and more particularly to an optical module such as an optical connector or a hybrid connector and a pigtail type optical module.
2. Description of the Related Art
Hereinafter, a pigtail type optical module disclosed in the following Patent Document 1 will be described. In FIG. 6(a), a pigtail type optical module 1 includes an optical connector portion (not shown), a light receiving/emitting portion 3 connected and fixed to a circuit substrate 2, relay optical fibers 4, 4 in which one end is connected to the connector portion and the other end is connected to the light receiving/emitting portion 3, and an optical fiber holding component 5 for holding the optical fibers 4, 4 and preventing an unnecessary force from being applied to the light receiving/emitting portion 3.
In FIG. 6(b), the light receiving/emitting portion 3 is provided with an FOT at a light emitting side having a light emitting device and an FOT at a light receiving side having a light receiving device (of which only one is shown in the drawing) (hereinafter, referred to as FOT 6), an FOT case 7 for fixing the FOT 6, and a shield case 8 for preventing electromagnetic noise by covering the FOT 6 and the FOT case 7. The FOT 6 has a resin molded package portion 9 and a plurality of lead frames 10. Although not shown, four lead frames 10 are arranged in one row. (Because of two FOTs 6, eight lead frames 8 can be arranged in one row.) Each lead frame 10 is inserted and soldered into a connection hole of the circuit substrate 2 and is connected to a target circuit.
The FOT case 7 has a fixing portion 11 for fixing the package portion 9 of the FOT 6 and a lead frame fixing portion 12 for inserting and fixing each lead frame 10. Although not shown in detail, a portion (or optical fiber connection tube portion) denoted by reference numeral 13 in the FOT case 7 is fixed to the other end of the optical fiber 4, such that the other end faces the device of the FOT 6. The lead frame fixing portion 12 is formed in a comb tooth shape.
The shield case 8 is formed in a box shape. In this shield case 8, partially pin-shaped substrate connectors 14, 16, and 18 are formed. In the shield case 8, pressing portions 17, 17 (of which only one is shown in the drawing) are respectively formed to hold the FOT 6 by pressing a back surface of the package portion 9 of the FOT 6. Like the lead frames 10 of the FOT 6, the substrate connection portions 14, 16, 16 are respectively inserted and soldered into the circuit substrate 2 to be connected and fixed thereto.
The substrate connection portion 14 is arranged and formed to both left and right sides of the shield case 8. The substrate connection portion 15 is arranged and formed in the center of the front of the shield case 8. The substrate connection portion 16 is arranged and formed below each pressing portion 17 in the rear of the shield case 8.
In addition, the following Patent Document 2 can also be considered as the related art.
Patent Document 1: JP-A-2005-91416
Patent Document 2: JP-A-2004-20894
However, since the pressing portion 17 of the shield case 8 has a structure for pressing the package portion 9 of the FOT 5 in the above-described prior art and the shield case 8 is manufactured by processing a thin metal plate, there is a problem in that the rear of the shield case 8 may be bent as shown in FIG. 6(c) (see a virtual line of the drawing with exaggeration). Accordingly, the pin-shaped substrate connection portion 16 may be also displaced. When the substrate connection portion 16 is displaced, its end position is shifted, such that a connection with the circuit substrate 2 may not be smoothly established. These are problems occurring in the prior art (or problems occurring in the techniques of Patent Documents 1 and 2).
It is difficult to correct the bend occurred in the rear of the shield case 8 in a job site of an assembly line. Bending and adjusting the substrate connection portion 16 is taken as an emergency treatment. This is the very complex work.